Generally, image displaying apparatus is classified into a panel type and a tubular type. In the panel type, there are EL (Electro Luminescent), PDP (Plasma Display Panel) and LED (Light Emitting Diode), etc., and in the tubular type, there are CRT (Cathode Ray Tube), etc.
As shown in FIGS. 1A to 1B, the plane type image displaying apparatus is constituted as described below. Pixels 2 are arranged in a transparent substrate 1 and connected to ICs 3 and 4. If image signals photographed by means of a camera are transmitted through the ICs 3 and 4 to the pixels 2, then the pixels 2 become luminescent for making a picture.
Meanwhile, tubular image displaying apparatus is constituted as illustrated in FIG. 1C and as described below. Pixels 12 are formed in the front panel of a picture tube 11 by spreading a phosphorescent material thereon, and a shadow mask 13 is installed in the picture tube 11 in such a manner as to keep a proper gap away from the front panel of the picture tube 11. Further, in the other portion of the picture tube 11, an electron gun 14 and a deflecting yoke 15 are installed. Electron beams projected by the electron gun 14 are deflected by the deflecting yoke 15, and impinged on the pixels 12 after passing through the shadow mask 13, so as for the pixels 12 to become luminescent and to make a picture.
However, the above described image displaying apparatus produce only plane images, i.e., 2-dimensional images, to users' unsatisfactorily. Therefore, recently there have been proposed stereoscopic image displaying apparatus for displaying images in a 3-dimensional form.
As shown in FIGS. 2A and 2B, the pixels of the image displaying apparatus consists of odd column pixels 22a and even column pixels 22b, in which the odd column pixels 22a are connected to a column driving IC 23 and to a row driving IC 25 for left image signals and the even column pixels 22b are connected to a column driving IC 24 and to a row driving IC 25 for right image signals.
Further, in front of the pairs of the odd column pixels 22a and the even column pixels 22b, there is installed a convex lens screen 26 as a stereoscopic image producing means. The stereoscopic image displaying apparatus 21 as described above can be also applied to the tubular displaying apparatus such as cathode ray tube.
The stereoscopic image displaying apparatus 21 is operated as described below. An object is photographed by two cameras, and the image signals photographed by means of the left camera are sent to the column driving IC 23 for left image signals, while the image signals photographed by the right camera are sent to the lateral row driving IC 24 for right image signals. Then the left image signals energize the odd columns pixels 22a and the light rays therefrom is projected to the left after being refracted by the front convex lens 26 screen in the direction of arrows "L" of FIG. 2B. Meanwhile, the right image signals energize the even column pixels 22b and the light rays therefrom are projected to the right after being refracted by the front convex lens screen 26 in the direction of dotted arrows "R" of FIG. 2B.
Therefore, if a person watches the screen from the front, the image of the object photographed by the left camera is seen by the left eye of the watching person, and the image of the object photographed by the right camera is seen by the right eye of the watching person, thereby obtaining a stereoscopic effect.
However, such a stereoscopic effect can be obtained when the watching user is positioned at the exact front or within a limited angular range. However, if the user departs from the limited angular range, either set of the leftward or rightward projecting images cannot be seen by the user, or confusion is caused so as for the eyes of the watching user to be tired, thereby degrading the stereoscopic effect.